Methods of electrophoresis in which ionic substances are separated in a solution by using such separating carriers as paper, cellulose acetate film, starch gel, polyacrylamide gel, etc., are classified into zone electrophoresis methods and isoelectric focusing. Both of these methods have been widely used as means for separating proteins, enzymes, or the like.
A conventional electrophoretic apparatus is constituted by an electrophoretic separating part and a source part. Although the conventional electrophoretic separating part provides an excellent performance, its mechanical construction is complicated and expensive, and the electrophoretic portion cannot readily be used. Where only one sample can be separated with only one electrophoretic operation as a two dimensional electrophoresis using a combination of isoelectric focusing and carrier focusing (which became the usual practice), or where electrophoresis is required to be performed under various separating conditions, it is necessary to use a plurality of electrophoretic apparati, which is uneconomical.
The electrophoretic separating part of the electrophoretic apparatus comprises as its essential elements a separating carrier, positive and negative two electrode tanks respectively containing electrolyte, electrodes for passing electric current through solutions contained in respective tanks, and a bridge which ionically and conductively couples together the electrodes and the separating carrier, and which has a relatively simple construction.
When current is passed, the separating carrier generates heat which degrades the separation performance and denatures the separated substance so that it is necessary to provide means for cooling the separating carrier. Such cooling means not only occupies a substantial portion of the electrophoretic apparatus but also complicates its construction.
Accordingly, it is an object of this invention to provide an improved electrophoretic apparatus having a simple construction which can be formed at a low cost by simplifying the construction at the cooling means for the separating carrier.
Another object of this invention is to provide an improved electrophoretic apparatus capable of preventing condensation formed on the outer surface of a cooling tank, which cooling tank is provided for cooling the separating carrier, from invading into a gel film portion contributing to the electrophoresis. The apparatus can then be used for the zone electrophoresis and for the isoelectric focusing.
A further object of this invention is to provide a novel electrophoretic apparatus that can increase the upper limit of the applied voltage above that of any known prior art electrophoretic apparatus.